Universal Fire Caused by Stagehands?

From the Theme Park Insider blog comes news the the massive Universal fire may have been started by some a set construction crew?: 

 Universal Studios fire sparked by blow torch

By Steve Gorman Mon Jun 2, 9:52 PM ET

LOS ANGELES (Reuters) - A fire that burned through a large swath of the Universal Studios Hollywood back lot during the weekend was accidentally sparked by workers using heating tools on a film set, fire officials said on Monday.

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He said an investigation revealed the fire was touched off by three members of a studio work crew who had been using a blow torch to apply asphalt shingles to the roof of a building facade.

They finished their work at about 3 a.m. and stood watch for an hour, according to company policy. Seeing no signs of a fire, they left the scene for a break, but a security guard in the vicinity noticed flames about 45 minutes later and called the fire department.

 In any case, it's amazing to me that the studio didn't have a better fire response and weren't able to contain the fire.  I know they had low water pressure, etc., but this is LA, home of wildfires, etc., and the same area was destroyed by an arson fire previously.